Upx: heap-buffer-overflow in packtmt::pack()
Priority LOW 25CWE-787Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-787 and the CVSS impact.
Summary
A heap-based buffer overflow issue was discovered in UPX in PackTmt::pack() in p_tmt.cpp file. The flow allows an attacker to cause a denial of service (abort) via a crafted file.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00398 34th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed upx: 4.0.2
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | upx | — | 4.0.2 | Patch available | CNA |
- upx Vendor— Affected — Fixed in 4.0.2 Patch available CNA
CPE configurations NVD · 3
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:upx:upx:*:*:*:*:*:*:*:* | before 2022-11-24 | Vulnerable | Upx |
| cpe:2.3:o:fedoraproject:fedora:36:*:*:*:*:*:*:* | 36 | Vulnerable | Fedoraproject |
| cpe:2.3:o:fedoraproject:fedora:37:*:*:*:*:*:*:* | 37 | Vulnerable | Fedoraproject |
- cpe:2.3:a:upx:upx:*:*:*:*:*:*:*:* Versions before 2022-11-24 Vulnerable ·Upx
- cpe:2.3:o:fedoraproject:fedora:36:*:*:*:*:*:*:* Versions 36 Vulnerable ·Fedoraproject
- cpe:2.3:o:fedoraproject:fedora:37:*:*:*:*:*:*:* Versions 37 Vulnerable ·Fedoraproject
Remediation
- Fix · CNA upx Fixed in 4.0.2
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2023-23456
- 2026-10-03 Alias added: GHSA-3j7g-922g-j6r3
References
Sources
- CVE-2023-23456 · CVE Program
- CVE-2023-23456 · NVD
- FIRST EPSS
- GHSA-3j7g-922g-j6r3 · GitHub Advisory Database · CC BY 4.0
- CVE-2023-23456 · Red Hat security data · CC BY 4.0
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